Custom-moulded ear-plug device

ABSTRACT

A hearing aid ear-plug device and process for its manufacture, including a resilient, custom-molded outer shell adapting to the dynamics of its area of application including the ability to adapt to dynamic movement of the auditory canal. The outer shell may include fins and/or ribs integrated internally or externally with the shell. Any internal components of the device are protected while ensuring the structural stability of the device.

BACKGROUND OF THE INVENTION

The invention addresses problems which have been encountered especiallywith in-ear hearing aids.

In-ear hearing aids are typically produced by first making an impressionof the ear canal and then molding the custom-moulded ear-plug shell fromthe impression. Yet in the ear canal, in-ear hearing aids are exposed tosubstantial dynamic movement of the area of application, i.e. theauditory canal, for instance during mastication, so that,notwithstanding a precisely adapted fit of the hearing aid based on theimpression with subsequent fine adjustment, in practice the device isnot fully satisfactory in terms of wearing comfort. This is due in partto the fact that the usually rigid custom-moulded ear-plug shells cannotabsorb the aforementioned dynamic movement. On the other hand, in thebasic design of the hearing-aid shell especially in the case of in-earhearing aids, consideration must always be given to the need forminiaturization, the accommodation of complex electronic modules and theassurance of reproducible, stable acoustic conditions.

However, the problem of dynamic movement of the area of application,encountered with in-ear hearing aids, also presents itself with othercustom-moulded ear-plug devices, albeit often to a lesser extent,devices which in practice are worn on other parts of the body and whichin daily life are subjected to a certain dynamic movement. In otherwords, while the problem is particularly pronounced in the case ofin-ear hearing aids and, obviously, of in-ear custom-moulded ear-plugdevices in general, for instance parts of earphones, noise- orwater-blocking ear plugs, it also exists for pinnal hearing aids andcustom-moulded ear-plug devices.

SUMMARY OF THE INVENTION

It is the objective of this invention to introduce custom-mouldedear-plug devices which solve the above-mentioned problems, in dueconsideration of the severely restricted physical space available forin-ear custom-moulded ear-plugs and especially in view of the stringentrequirements for in-ear hearing aids in terms of their acousticproperties. This is accomplished in that, at least in one section of itsouter surface and/or, in the case of an custom-moulded ear-plug shell,of its inner surface, the custom-moulded ear-plug device features apattern of longitudinally elongated profiles, or, if the custom-mouldedear-plug device is provided with a shell constituting its outer surface,in that at least one section of the inner surface of said shell featuresa pattern of longitudinally elongated profiles.

The structural pattern thus produced determines in regionally specificfashion the flexibility and/or compressibility of the custom-mouldedear-plug unit. For example, following the proposed approach it ispossible to configure the elongated profiles in the form of structurallystabilizing fins or ribs on what is otherwise a relatively thincustom-moulded ear-plug shell. The layout, contouring and density of theribs are by themselves entirely capable of ensuring the flexibility ofthe custom-moulded ear-plug device that is necessary for absorbing thedynamic movement inherent in the application.

In a preferred embodiment of the custom-moulded ear-plug deviceaccording to this invention, a combination of the above-mentionedfeatures is employed, i.e. the shell of the custom-moulded ear-plug unitis provided with both inner and outer profiles. Where for ancustom-moulded ear-plug device compressibility and/or flexibility isrequired in a relatively well-defined section, it is suggested that theprofiles in that area extend along continuous closed paths around thecustom-moulded ear-plug unit, preferably in an undulating orbellows-like pattern. Looking for instance at an in-ear custom-mouldedear-plug device with a profile orientation between an area facing thetympanic membrane and an area facing the pinna, i.e. the opening of theauditory canal, and if the longitudinal direction of the custom-mouldedear-plug device is defined as extending between these two areas, itbecomes evident that the mentioned configuration of the profiles,following continuous, closed or helical paths in planes essentiallyperpendicular to the said longitudinal direction, leads to asubstantially enhanced flexibility or compressibility of thecustom-moulded ear-plug unit. This is especially true if the profiles onthe inner and outer surfaces are mutually offset in the aforementionedlongitudinal direction and the profiles are formed by protuberances ofthe shell wall proper.

In another preferred design implementation, also easily combinable withthe aforementioned embodiment, the profiles form a grid pattern in atleast one section of the custom-moulded ear-plug unit, providing a localmechanical reinforcement of the custom-moulded ear-plug unit in thatsection and, if the latter is in the form of a shell; allowing the areasbetween the profiles to be extremely thin-walled. A grid or latticepattern of this nature produces a high level of dynamic absorptivitywhile in the case of custom-moulded ear-plug units with a shell alsopermitting the use of an extremely thin-walled shell, reinforced only bythe said profiles. The orientation and the cross-sectional dimension ofthe profiles provided are determined by varying profile shapes, whichoffers another measure of design flexibility in defining the mechanicalproperties of the custom-moulded ear-plug device according to thisinvention. Yet another design parameter that can be added consists in ashape variation of the profiles over their longitudinally extendedpaths.

In summary, the proposed design features will yield custom-mouldedear-plug devices individually customizable in specific regions inadaptation to the particular requirements relative to their structuralproperties, meaning flexibility and compressibility. The concept perthis invention is implementable with virtually no added bulk, since theproposed profiles permit a reduction of the wall thickness of thecustom-moulded ear-plug shells. At the same time, the acousticrequirements can be fully satisfied, given that by means of the featuresper this invention such as localized reinforcements. the mechanicalproperties of the custom-moulded ear-plug shell or fully enclosedcustom-moulded ear-plug device can be optimized.

If the custom-moulded ear-plug device is designed as an in-earcustom-moulded ear-plug unit with a region facing the eardrum andanother region facing the outer ear, it is recommended that the profileson the outer surface of the custom-moulded ear-plug unit be providedwith at least one groove freely extending between the mentioned regionsand defining a venting groove.

The last-mentioned measures per this invention also make it possible toeasily provide for air to reach the tympanic membrane.

Another preferred design version of the custom-moulded ear-plug deviceper this invention features a shell with the above-mentioned profiles aswell as a filler material contained in and essentially filling the shelland adapted to the intended function of the custom-moulded ear-plugunit.

If the custom-moulded ear-plug device according to this invention is toincorporate certain modules such as electronic components, batteries,converters etc., as is the case especially with hearing aids, it isrecommended that, in the design version last mentioned, a cavity orreceptacle be provided within the filler material for accommodating suchmodule or modules in the custom-moulded ear-plug unit.

Another embodiment of the custom-moulded ear-plug device per thisinvention is already equipped with the above-mentioned modules and ispreferably designed as a hearing aid and most preferably as an in-earhearing aid.

The following describes implementation examples of this invention, andother custom-moulded ear-plug design versions combinable therewith, withthe aid of the attached drawings in which:

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a simplified schematic illustration of a production system forthe industrial i.e. commercial fabrication of custom-moulded ear-plugdevices optimized by a preferred manufacturing process;

FIG. 2 illustrates another system concept analogous to that in FIG. 1;

FIG. 3 shows yet another system concept analogous to that in FIGS. 1 and2;

FIG. 4 is a schematic illustration of an in-ear hearing aid provided inconventional fashion with a cerumen protection cap;

FIG. 5 shows, analogous to FIG. 4, an in-ear hearing aid with anintegrated cerumen protection cap;

FIG. 6 shows an in-ear hearing aid with a conventionally machinedventing groove;

FIG. 7(A) to (f) are perspective illustrations of sections ofcustom-moulded ear-plug shell surfaces provided with venting grooves;

FIG. 8 is a schematic illustration of an custom-moulded ear-plug surfacesection with a venting groove which, in its longitudinal direction,varies in both the size and shape of its cross section;

FIG. 9 is a schematic depiction of an in-ear custom-moulded ear-plugunit with an extended venting groove;

FIG. 10 is an illustration, analogous to that in FIG. 9, of an in-earcustom-moulded ear-plug device with several venting grooves;

FIG. 11(a) to (e) show custom-moulded ear-plug shell sections withventing channels of varying crosssectional shapes and dimensions;

FIG. 12 is an illustration, analogous to that in FIG. 8, of a ventingchannel in an custom-moulded ear-plug shell, varying along itslongitudinal direction in its cross-sectional shape or surface;

FIG. 13 is a schematic illustration, analogous to that in FIG. 9, of anin-ear custom-moulded ear-plug unit with an extended, machined ventingchannel;

FIG. 14 is an illustration, analogous to that in FIG. 10, of an in-earcustom-moulded ear-plug unit with several venting channels;

FIG. 15 shows in schematic fashion a longitudinal section of an in-earcustom-moulded ear-plug unit per this invention, with a ribbed innersurface;

FIG. 16 is a cross-sectional partial view of the custom-moulded ear-plugunit per this invention as shown in FIG. 15, featuring ribs with varyingcross-sectional surfaces;

FIG. 17 is a perspective view of part of an custom-moulded ear-plugshell per this invention, with inside ribbing as in FIG. 15 or 16, saidribs featuring along their longitudinal direction varyingcross-sectional shapes and dimensions;

FIG. 18 is an illustration, analogous to that in FIG. 15, of an in-earcustom-moulded ear-plug unit with exterior ribbing per this invention;

FIG. 19 is a schematic, partial illustration of a ribbed custom-mouldedear-plug shell per this invention as shown in FIG. 18, with the ribsfeaturing varying cross-sectional surfaces;

FIG. 20 is a schematic, cross-sectional view of an custom-mouldedear-plug unit per this invention, with exterior ribbing, or internalribbing as the case may be, and with at least part of the inner spacecontaining filler material;

FIG. 21 shows in schematic fashion a longitudinal section of ancustom-moulded ear-plug shell per this invention featuring a flexibleand compressible segment;

FIG. 22 shows in schematic fashion a longitudinal section of an in-earcustom-moulded ear-plug unit with a cavity for accommodating anelectronic module;

FIG. 23 shows an custom-moulded ear-plug unit per FIG. 22, in theprocess of being slipped over an electronic module;

FIG. 24 is a perspective and schematic view of an in-ear custom-mouldedear-plug unit, especially of an in-ear hearing aid, with a two-part,separable and joinable custom-moulded ear-plug shell;

FIG. 25 is a partial, schematic illustration of the integration ofacoustic conductors and adapters connecting to an acoustoelectric orelectroacoustic converter in an custom-moulded ear-plug unit;

FIG. 26 is an illustration, analogous to that in FIG. 25, of the layoutof two or more acoustic conductors in the shell of an custom-mouldedear-plug unit; and

FIG. 27 shows, in the form of a simplified signal-flow/functional-flowblock diagram, a novel process and a novel implementation thereof,which, in the configuration of the custom-moulded ear-plug device, takesinto account the dynamics of the area in which the device is applied.

DETAILED DESCRIPTION OF THE INVENTION

The custom-moulded ear-plug-unit design versions discussed following thedescription of the production process are preferably all manufactured bythe said production process.

Definition

The term custom-moulded ear-plug device refers to a unit which isapplied directly outside the pinna and/or at the pinna and/or in theauditory meatus or ear canal. It includes external or pinnal hearingaids, in-ear hearing aids, headphones, noise- and water-blocking earplugs, and the like.

1. Production Process

In the preferred production process for fabricating the custom-mouldedear-plug devices described in detail further below, the shape of aparticular region in which an custom-moulded ear-plug unit is to beapplied, is digitized in three dimensions, whereupon the custom-mouldedear-plug unit or its shell is built up by an additive process. Additiveor incremental building i.e. composite structuring processes are alsoknown as Rapid Prototyping. For incremental processes of this nature,already employed in rapid prototyping, reference is made to:

The web site: tk.hut.fi/-koukka/RP/rptree.html (1)

Wohlers Report 2000, Rapid Prototyping & Tooling State of the Industry(2)

The different incremental processes currently known and employed inrapid prototyping indicate that laser sintering, laser or stereolithography or the thermojet process are particularly well suited to thebuilding of custom-moulded ear-plugs or their shells and especially thespecific configurations described below. These preferred additivestructuring processes are therefore briefly summarized as follows:

Laser sintering: A thin layer of hot-melting powder is applied on apowder bed for instance by means of a roller. A laser beam, controlledby the 3D data of the specific individual application area, solidifiesthe powder layer that corresponds to a slice or sectional layer of thecustom-moulded ear-plug unit or shell. A solid sectional layer of thecustom-moulded ear-plug unit or shell is thus produced in the otherwiseloose powder. That layer is then lowered out of the powder depositionplane and a new powder layer is superposed, laser-solidified toconstitute another sectional layer, etc.

Laser or Stereo lithography: A first sectional layer of thecustom-moulded ear-plug unit or shell is solidified on the surface of aliquid photopolymer by means of a UV laser. The hardened layer is dippedand again covered with the liquid polymer. By means of the UV laser thesecond sectional layer of the custom-moulded ear-plug unit or shell issolidified on the first hardened layer.

The positional movement of the laser is itself controlled by the 3D dataof the specific application area previously digitized.

Thermojet Process: The contouring for a given sectional layer of thecustom-moulded ear-plug unit or shell follows a principle similar tothat of an ink jet printer, in that liquid is applied based on thedigitized 3D data especially of the specific area of application. Thesectional image deposited is then allowed to solidify. Again followingthe principle of an incremental buildup, layer upon layer is depositedin building the custom-moulded ear-plug unit or shell.

Relative to additive structuring processes, including theabove-mentioned preferred process, reference is made to these otherpublications:

The web site: www.padtinc.com/srv_rpm_sis.htm (3)

“Selective Laser Sintering (SLS) of Ceramics”, Muskesh Agarwala et al.,presented at the Solid Freeform Fabrication Symposium, Austin, Tex.,August 1999 (4)

The web site: www.caip.rutgers.edu/RP_Library/process.html (5)

The web site: www.biba.uni-bremen.de/groups/rp/lom.html or

The web site: www.biba.uni-bremen.de/groups/rp/rp_intro.html (6)

Donald Klosterman et al., “Direct Fabrication of Polymer CompositeStructures with Curved LOM”, Solid Freeform Fabrication Symposium,University of Texas at Austin, August 1999 (7)

The web site: lff.me.utexas.edu/sls.html (8)

The web site www.padtinc.com/srv_rpm_sla.html (9)

The web site: www.cs.hut.fi/-ado/rp/rp.html (10)

Thus, the basic principle employed in the incremental-buildup oradditive-structuring process consists in the deposition of a thin layerof material on a surface, whether that is a full-surfaced blank as inlaser sintering or in stereo lithography, or, as in the thermojetprocess, already a contoured section of the custom-moulded ear-plug unitor shell that is being constructed. The desired sectional shape is thenstabilized, i.e. hardened.

Once a layer has hardened, a new layer is deposited on it as describedabove, hardened and bonded to the finished layer underneath. In thatfashion, layer by layer, the custom-moulded ear-plug unit or shell iscomposed by the successive, additive deposition of multiple layers.

In commercial production, the preferred method is not to separatelydeposit and solidify each individual sectional layer for a singlespecific custom-moulded ear-plug unit or shell, one at a time, but tosimultaneously produce several layers for each unit. For example, inlaser sintering one laser, typically mirror-controlled, solidifies thesectional layers of several custom-moulded ear-plug units or shellsbefore all hardened sectional layers are jointly dipped. Thereupon,after a new powder layer has been deposited on all hardened and dippedsectional layers, the next multiple sectional layers are formed.Although fabricated in parallel, the individual custom-moulded ear-plugunits or their shells are produced as separate units under appropriatedigital control.

The solidification of multiple sectional layers employs either a singlelaser beam or more than one laser beam operated and controlled inparallel.

In an alternative process, a sectional layer is individually solidifiedby a laser while concurrently a powder layer is deposited for forminganother custom-moulded ear-plug unit or shell. Subsequently that samelaser is used to solidify the prepared powder layer representing thesectional layer for the next custom-moulded ear-plug element, while thepreviously solidified layer is dipped and a new powder layer isdeposited on it. In this case the laser alternates intermittentlybetween two or several custom-moulded ear-plug units or shells which arebeing fabricated, while the idle time of the laser otherwise occurringduring the powder deposition for the forming of one of the shells isutilized for the solidification of a sectional layer of anothercustom-moulded ear-plug unit that is being built.

FIG. 1 is a schematic illustration of one process variant in which, bylaser sintering or laser or stereo lithography, several custom-mouldedear-plug units or their shells are commercially manufactured in aparallel process. The laser with its control unit 5 and its beam 3 islocated above the bed of powder or fluid material. In its position 1 itsolidifies the layer S₁ of a first custom-moulded ear-plug unit or shellunder the control of the first discrete data set D₁. Thereupon, arepositioning device 7 moves it into a second position where, under thecontrol of the second discrete data set D₂, it produces the layer S₂following another specific contour. Of course, several of the lasers maybe moved in unison, for the simultaneous production of more than oneindividual custom-moulded ear-plug layer. Not until the appropriatelasers 5, in all their predefined positions, have produced the variousindividual layers in the laser sintering process will a new powder layerbe deposited by the powder feed system 9 or, in the case of laser orstereo lithography, will the solidified layers S be dipped in the fluidbed.

As shown in FIG. 2, several individually controlled lasers 5, operatingin parallel, simultaneously solidify layers of individual custom-mouldedear-plug units or shells in one or more fluid or powder beds 1. Again,upon completion of this solidification phase and deactivation of thelasers, the powder feed unit 9 deposits a new powder layer, while in thecase of laser or stereo lithography the layers just solidified or thealready hardened structures are dipped in the fluid bed.

As shown in FIG. 3, the laser 5 solidifies the layer S₁ in one powder orfluid bed 1 a, then moves over to bed 1 b (dotted line) where, duringthe solidification phase at bed 1 a, the powder deposition device 9 bapplies powder on a previously solidified layer S¹⁻ or, in the case oflaser or stereo lithography, the layer S₁ is dipped. Not until the laser5 is activated at bed 1 b will the powder feed unit 9 a deposit a newpowder layer at bed 1 a on the layer S₁ just solidified, or will thelayer S₁ be dipped in the fluid bed 1 a.

When employing the thermojet process, and for correspondingly increasedproductivity, sectional layers are simultaneously deposited for morethan one custom-moulded ear-plug unit or shell, essentially in onesingle stroke by one applicator head or by several such heads operatingin parallel.

The process described makes it possible to produce custom-mouldedear-plug units or shells of highly complex shapes both in terms of theirouter contours and, in the case of a shell, of its inner contours, withindividualized adaptation to the area of application concerned. Ledges,recesses and protrusions can be easily configured.

There also exist materials for the incremental build-up process whichcan be shaped into an elastic yet sturdy shell which latter, if desired,can vary in thickness down to an extremely thin yet break-resistantwall.

In a currently preferred implementation the digitizing of the specificindividual areas of application, especially those for a hearing aid andin particular for an in-ear hearing aid, is performed at a specializedinstitution, in the latter case by an audiologist. The individual imageinformation in the form of digital 3D data, especially those for hearingaids, is transmitted to a production center either on a disk or via theInternet. The production center then fabricates the individualcustom-moulded ear-plug unit or shell, in the case discussed an in-earhearing-aid shell, employing in particular the above-mentioned process.The center preferably also performs the complete assembly of the hearingaid with the appropriate functional components.

Due to the fact that, as mentioned above, the thermoplastic materialsemployed generally allow for a relatively elastic outer contour with asnug fit, the problem of pressure points in the shaping ofcustom-moulded ear-plug units or shells is far less critical than hasbeen the case in the past, a point of particular significance for in-earcustom-moulded ear-plugs. It follows that in-ear custom-mouldedear-plugs such as hearing aids, headphones, water-blocking devices andespecially in-ear hearing aids can be inserted much like elastic plugswhose surface adapts itself with a snug fit to the area of applicationi.e. the auditory meatus or ear canal. One or several venting channelscan be easily provided in the in-ear custom-moulded ear-plug unit,ensuring that, notwithstanding the resulting, perhaps relatively tightfit of the custom-moulded ear-plug unit in the ear canal, the air flowto the ear drum remains uninhibited. In the production process, thespecific 3D data for the area of application can also be mostadvantageously employed for optimizing the inner configuration of theplastic unit, even including the accommodation and constellation of anycustomized components as in the case of a hearing aid.

Specifically for custom-moulded ear-plugs in the form of hearing aids,centralized shell production also allows for the centralized storing andmanagement of individual patient data both with regard to thepatient-specific area of application and to the individual functionalelements and their settings. If for whatever reason a shell must bereplaced, it can be reproduced simply by retrieving the individual datasets, without requiring a laborious new fitting as in the past.

Given that processes for producing custom-moulded ear-plug devices,albeit prototypes only, have been part of prior art and have beendescribed in earlier literature, there is no need at this juncture torepeat all the technical details of these processes.

In any event, it has been surprising to find that adopting theseprior-art prototyping technologies yields rather substantial benefitsfor the industrial, commercially attractive production of custom-mouldedear-plugs, for reasons which for all practical purposes are of nosignificance in prototyping, such as the elasticity of suitablethermoplastic materials, the ability to customize extremely thin-walledelements, etc.

To summarize, employing the above-mentioned additive, incrementalbuild-up process in the production of custom-moulded ear-plug units orshells makes it possible to integrate in these various functionalelements, the configuration of which is already laid out in the computerduring the design phase of the custom-moulded ear-plug unit and whichare installed as the custom-moulded ear-plug unit or shell is produced.In the past, such functional elements were typically retrofitted oradded to the finished custom-moulded ear-plug unit or shell, asevidenced by seams at junctions of different or inhomogeneous materialsat the points of assembly.

For the custom-moulded ear-plugs discussed and especially thosecontaining electronic components, such as hearing aids and especiallyin-ear hearing aids, the components which can be integrated directlyinto the custom-moulded ear-plug shell by the technique proposedinclude, by way of example, the following:

Component mounts and holders, cerumen-protection systems, ventingchannels in the case of in-ear custom-moulded ear-plugs, or channellocks which keep in-ear custom-moulded ear-plugs in. place in theauditory canal.

FIG. 4 schematically illustrates an example of an in-ear custom-mouldedear-plug unit 11 such as an in-ear hearing aid whose acoustic port 13 onthe ear-drum side is provided with a cerumen-protection cap 15. In pastproduction processes, such a protective cap 15 would be mounted as aseparate part on the shell 16 of the custom-moulded ear-plug unit 11 andfastened for instance with glue or by welding. When employing theaforementioned additive build-up process, as shown in an identicalillustration in FIG. 5, the cerumen protection cap 15 a is integrateddirectly into the shell 16 a of the otherwise identical in-earcustom-moulded ear-plug unit 11 a. At the junctions, schematicallyidentified as P in FIG. 4, conventional processes would necessarily leadto material inhomogeneities or seams whereas in the case depicted inFIG. 5 there is no such seam and the material of the shell 16 ahomogeneously transitions into that of the cerumen-protection cap 15 a.

This is only one example of how conventional cerumen-protection systemsand other functional elements can be directly integrated by employingthe abovementioned production process.

The following will introduce a few specific, novel custom-mouldedear-plug devices:

2. Vented Inner-Ear Custom-moulded Ear-plugs

It is a conventional practice in the case of in-ear custom-mouldedear-plugs and especially in-ear hearing aids to provide a venting grooveon the outer surface, as schematically illustrated in FIG. 6. Ascurrently used venting grooves go, they are by no means optimized withregard to various features:

Acoustic properties: Prior-art venting grooves are not really adapted tothe different acoustic requirements. For example, in activecustom-moulded ear-plug devices such as in-ear hearing aids theycontribute next to nothing to an effective solution of the feedbackproblem between the electromechanical output converter and theacoustoelectric input converter. In passive in-ear custom-mouldedear-plugs such as ear protectors, they do not provide the desired levelof protection while at the same time maintaining good ventingproperties.

Susceptibility to cerumen: The venting grooves currently provided on theouter surfaces of in-ear custom-moulded ear-plugs are extremelysusceptible to the formation of cerumen. Depending on its intensity,cerum buildup can quickly limit the air-conducting capacity of theventing grooves by constricting or even fully clogging them.

The following describes proposed venting solutions for in-earcustom-moulded ear-plugs and especially for in-ear hearing aids orear-protection devices, but also for custom-moulded ear-plugs which onlypartly protrude into the ear canal, such as headphones, which solutionseliminate at least in part the above-mentioned shortcomings ofconventional provisions.

In this context, one differentiates between venting systems which

are essentially in the form of a groove which at least in part opens uptoward the wall of the ear canal,

are channels completely closed toward the wall of the ear canal.

2a) Venting Systems which are Open Toward the Wall of the Ear Canal

In FIGS. 7(a) to (f), the perspective, schematic partial illustrationsof the outer wall 18 of in-ear custom-moulded ear-plugs, resting againstthe ear canal, depict sections of innovative venting-channelconfigurations. In FIG. 7(a), the cross section of the venting groove 20a is square or rectangular with precisely defined and maintaineddimensional parameters. In FIG. 7(b) the venting groove 20 b has a crosssection in the form of a circular or elliptic sector, again with aprecisely defined lateral curvature 21 b. Such precise definition andimplementation of the cross-sectional shape of the venting grooves 20already allows for a certain predictability and control of the acousticpropagation characteristics along the groove when that is in flushcontact with the inner wall of the ear canal. Of course, the acousticproperties also depend on the length over which the groove 20 extendsalong the outer surface 18 of the custom-moulded ear-plug unit.

FIGS. 7(c) to (f) illustrate other venting-channel cross sections,additionally provided with cerumen protection. The groove per FIG. 7(c)has a T-shaped cross section.

In relation to the wide cross-sectional base of the groove in FIG.27(c), the cantilevering of the sides 23 c and resultant narrowing 25 cin the direction of the ear-canal wall already provides an appreciablemeasure of cerumen protection. Even if cerumen penetrates into thenarrow part 25 c and hardens there, it will not cause any substantialconstriction, never mind clogging, of the venting groove, but will onlymake it an enclosed venting channel. Following the principle explainedin relation to FIG. 7(c), FIGS. 7(d) to 7(f) show the widecross-sectional base 27 d to 27 f of the venting groove in variousshapes, such as a circular or elliptic sector per FIG. 7(d), triangularas in FIG. 7(e), or circular or elliptical as per FIG. 7(f).

A specific, precise design of the cross-sectional surface of the groove,as illustrated by way of only a few examples in FIGS. 7(a) to 7(f),already leads to acoustic as well as cerum-protection properties whichare measurably superior to those of conventional, more or lessrandom-shaped venting grooves. For the desired cerumen-protection andacoustic properties, the cross sections are first computer-modeled andthen precisely integrated into the custom-moulded ear-plug productionunits. A particularly suitable way to accomplish this is to employ theadditive build-up processes explained above. Further optimization of theacoustic properties of the venting groove can be obtained by providingalong these novel venting grooves any given acoustic impedances; in FIG.8, for example, this results in venting grooves 29 which along theirlongitudinal direction feature progressively changing cross-sectionalshapes, selected and sequenced in FIG. 8 from cross-sections in FIG. 7.

In a manner similar to the design of passive electrical circuitry, theventing groove that is in contact with the ear canal can becomputer-modelled and tested for its acoustic transmission propertiesand then integrated into the in-ear custom-moulded ear-plug device orshell.

As illustrated in FIG. 8 at point A, it is possible to specificallyprovide multiple cerumen-protected sections in correspondingly exposedlocations.

It may also be altogether desirable especially with a view to optimizedacoustic properties to make the venting grooves longer than wouldnormally correspond to the basic length of a given in-ear custom-mouldedear-plug unit. As shown in FIG. 9, this is accomplished by cuttinggrooves 31 with shapes for instance as illustrated in FIG. 7 and 8 intothe surface of the custom-moulded ear-plug unit along predefined curves,as depicted in the example of FIG. 9, practically in the form of helicalgrooves surrounding the custom-moulded ear-plug unit. Enhanced, optimaldesign flexibility is obtained by providing not only one but severalventing grooves on the surface of the custom-moulded ear-plug unit, asschematically illustrated in FIG. 10. This substantial measure of designflexibility makes it possible to configure and variably dimension theventing grooves on the surface of the custom-moulded ear-plug unit so asto optimize cerumen protection and acoustic transmission properties forany particular area of application in the ear canal.

2b) Venting Systems with Fully Integrated Channels

This design variation of the innovative venting systems consists ofventing channels which are at least in some sections fully integratedinto the custom-moulded ear-plug unit and closed off against the wall ofthe ear canal. A system of this type, designed into an custom-mouldedear-plug shell, is described below. However, it should be stressed that,if no further modules need to be integrated in the custom-mouldedear-plug unit discussed and if the latter is a solid plastic body, thefollowing statements naturally also apply to any desired routing ofchannels through the solid plastic body in question.

Analogous to FIG. 7, FIG. 11 illustrates various cross-sectional shapesand surface distribution patterns of the proposed venting channels 33 ato 33 e. In FIG. 11(a) the venting channel 33 a integrated into thecustom-moulded ear-plug shell 35 a has a rectangular or square crosssection, in the design version per FIG. 11(b) the cross section of thechannel 33 b is in the form of a circular or elliptic sector. In thedesign variant per FIG. 11(c) the cross section of the venting channel33 c is circular or elliptic while in the design variant per FIG. 11(d)it is triangular.

In the embodiment per FIG. 11(e) the custom-moulded ear-plug shellfeatures a complex interior shape, for instance with an integratedretaining-strip extension 37. For optimal space utilization the crosssection of the associated venting channel 35 e is so designed as to takeadvantage even of complex shape variations of the custom-mouldedear-plug shell. Accordingly, part of its equally complex cross-sectionalform runs into the retaining strip 37 extending from the shell 35 e.

Going back to the design variant per chapter 2a) it should be mentionedthat this type of complex cross-section which offers optimal utilizationof the available space can equally well be chosen for venting groovesthat are open toward the wall of the ear canal and, conversely, thechannel patterns illustrated in FIGS. 9 and 10 for open grooves can beused for closed venting channels as well.

FIG. 12 finally illustrates a design version of a fully integratedventing channel 39 which in its longitudinal direction, for instance inthe depicted custom-moulded ear-plug shell 41, features varying crosssections and/or cross-sectional dimensions so that, with differentacoustic impedance elements, the acoustic transmission properties can beoptimized. In this context, and with reference to chapter 5) below, itshould also be pointed out that the ability to produce complex acousticimpedance characteristics makes it entirely possible to simultaneouslyutilize at least certain sections of the venting channels, andespecially of the closed designs discussed here, as acoustic conductoroutput sections of active electromechanical converters, like on theoutput side of microphones, for instance in the case of in-ear hearingaids.

Analogous to FIGS. 9 and 10, FIGS. 13 and 14 show how ina givencustom-moulded ear-plug unit 43 the integrated venting channelsexplained in this chapter can be extended by appropriate routing, and,respectively, how two or more of these channels can be integrated intothe custom-moulded ear-plug unit, perhaps with different and/or varyingchannel cross sections analogous to FIG. 12.

These capabilities, described in chapters 2a and 2b and combinable inany desired fashion, open up to the expert innumerable design-variationopportunities for the novel venting systems and most of all, in view ofthe various and variously dimensionable parameters, considerable leewayin providing for each individual custom-moulded ear-plug unit optimalcerumen protection as well as optimal acoustic transmission properties.For all design variants the specific individualized system configurationis preferably calculated and computer-modeled for the requirements athand and the corresponding custom-moulded ear-plug unitcustom-fabricated. And again, a particularly suitable way to accomplishthis is to employ the production process first above explained, based onthe additive building principle known from rapid prototyping andcontrolled by the optimized modeling data.

3. Optimized Structural Stability of Custom-moulded Ear-plug Units

This chapter serves to introduce novel custom-moulded ear-plugs whichare optimally adapted to the dynamics of the area of application. Forexample, it is a known fact that, due to their essentially uniformdegree of structural stability, conventional custom-moulded ear-plugin-ear devices cannot adapt to the relatively strong dynamic movement ofthe auditory canal for instance during mastication. Similarly, theacoustic conductors for instance between pinnal i.e. external hearingaids and the auditory canal cannot freely follow a dynamic movement ofthe area of application. In the case of in-ear custom-moulded ear-plugs,and with ear protectors, earphones, water-repellent ear plugs etc., thesame problem is encountered, albeit in part to a lesser degree. Mostimportant, some of their intrinsinc functionality such as theirprotective effectiveness are compromised the more an allowance is madefor the aforementioned dynamics of the area of application. Referencecan be made for instance to conventional ear protectors made of anelastically deformable plastic material which, although adapting to thementioned dynamics of the area of application, do so at the expense oftheir acoustic transmission characteristics.

FIG. 15 shows in schematic fashion a longitudinal section of an in-earcustom-moulded ear-plug device, FIG. 16 schematically illustrates partof the cross section of that same custom-moulded ear-plug unit. Thecustom-moulded ear-plug unit, for instance designed to accommodateelectronic components, includes a shell 45 which, sock-shaped, consistsof a thin-walled, elastic material. Where desired, the structuralstability of the skin of the shell, smooth on the outside in the designexample shown, is assured by means of fins or ribs 47 integrated intothe inside of the shell which ribs are of the same material as the skinof the shell.

The fins or ribs 47 physically project some distance from the inner orthe outer surface of the shell, locally increasing the thickness of saidshell and thus increasing the form stability and/or strength of saidshell, as shown in FIGS. 15-20. As also shown in these figures, theprojection amount is on the order of the thickness of the shell wheresaid shell is not covered by ribs. Further, the figure shows the addedrib projecting thickness not being substantially greater than thenon-ribbed shell portions' thickness, although the thickness can besubstantially less than the thickness of the shell areas without ribs,as shown in FIG. 17, for example.

Depending on the necessary dynamic adaptability of the in-earcustom-moulded ear-plug device for instance to match the dynamics of theauditory canal, and on the requirements in terms of channel locks andfor protecting built-in components as in the case of an in-ear hearingaid, the progression of the wall thickness of the shell skin 45 and thedensity and shape of the ribs 47 are computed in advance and thecustom-moulded ear-plug unit is built on the basis of the computed data.And again, the above-mentioned production method, employing the additivebuild-up process, is eminently suitable for the task. Of course, thedesign of the in-ear custom-moulded ear-plug unit as just explained canwithout question be combined with a venting system as described withreference to FIGS. 7 to 14. In particular, for modifying the degree ofrigidity i.e. flexibility in specific regions of the custom-mouldedear-plug unit the ribs can have varying cross sections which, ifdesirable, may also transition progressively along their longitudinalaxis from one cross section to another.

By way of a perspective illustration, strictly representing one typicalexample, FIG. 17 schematically shows the outer skin 45 with ribs 47, thelatter displaying varying cross-sectional surface dimensions in thelongitudinal direction.

In lieu of or in addition to the targeted wall reinforcement andpredefined bending and torsional characteristics, in short thestructural properties of the in-ear custom-moulded ear-plug unit, theinner ribbing as shown in FIGS. 17 and 18 may be complemented by anouter rib pattern as mentioned further above. To that effect, asindicated in FIG. 18 and 19, the outer surface of the custom-mouldedear-plug unit 49 is provided with a pattern of ribs 51 which may differregionally in terms of their density, orientation and cross section.

FIG. 19 shows that this approach can be taken with the hollow,cavity-type custom-moulded ear-plugs, but it is equally suitable forcustom-moulded ear-plug units without a cavity, for instance withoutelectronic components, and thus for devices such as ear protectors andwater-blocking ear plugs. The cross section of an custom-mouldedear-plug unit of this type is schematically shown in FIG. 20. In thiscase, the core 53 is made for instance of a highly compressibleabsorption material, surrounded by a contour-shaping skin 55 withribbing 57. The “skin” 55 and the ribbing 57 are produced jointly andintegrally, for which once again the production method first abovedescribed, employing the additive build-up process, offers itself. Towhat extent any such additive build-up process will be implementable anytime soon when applied to a work piece with inhomogeneous materials,remains to be seen. If that turns out to be possible, the road is clear,for instance in the case of the design example per FIG. 20, to alsobuild the filler 53 concurrently with the skin 55 and the ribs 57, layerby sequential layer.

Going back especially to FIGS. 18 and 19, it will be evident that theouter rib profiles can also double as delineators for venting channelsand/or free spaces, as is illustrated in purely schematic fashion by theexample of path P.

Referring back once again to FIG. 20, to the dotted line 57, it isentirely possible, if necessary, to provide the shell skin 55 with aninner rib pattern 57 even when the in-ear custom-moulded ear-plug unitis filled with a filler material and is not intended to accommodateother components such as electronic modules.

Moreover, as indicated by the dotted line 59 in FIG. 20, it is possibleto produce custom-moulded ear-plug units with a cavity for accommodatingmodules such as electronic components which cavity 59 is specificallyshaped to conform to the size and shape of these additional componentsto be installed, while at the same time the space between that cavityand the shell skin 55 is filled for instance with a resilient orsound-absorbing material or, alternatively, the components to beinstalled are embedded in such a material up to the shell skin 55.

The shell skin 55 or, respectively, 45 per FIGS. 15, 16 and 17, may infact be produced from an electrically conductive material, creating atthe same time an electrical shield for internally situated electroniccomponents. Where appropriate, this also applies to the filler material53 per FIG. 20.

FIGS. 15 to 20 illustrate an example of an in-ear custom-mouldedear-plug device whose shell is reinforced with inner and/or outer ribprofiles, allowing the structure to be exceptionally light-weight andcustomizable. Obviously, where necessary, this type of structure canalso be employed in outer-ear custom-moulded ear-plug units.

FIG. 21 shows another design variation of an in-ear custom-mouldedear-plug unit with a specific pliable and, respectively, compressiblesection. This is accomplished in that the shell 61 of an custom-mouldedear-plug unit, and in particular the shell of an in-ear hearing aid, isprovided in one or more predefined areas with a corrugated orbellows-like section 63 which is flexibly expandable or compressible tothe necessary extent. Although FIG. 21 illustrates this concept inconjunction with the shell of an in-ear custom-moulded ear-plug device,that concept, where necessary, is entirely implementable in a pinnalcustom-moulded ear-plug design as well. Again, the preferred productionmethod is as first above described.

In the case of this design example as well it is possible, as explainedin reference to FIG. 20, to fill the inner space of the custom-mouldedear-plug unit with the proper filler material for the purpose intended,or to embed integrated modules in such a filler material, thus obtainingimproved stability of the device as well as better acoustic properties.

4. Modular Housing and Build-ins

A problem especially with in-ear hearing aids consists in the fact thatthe shape of the area of application, i.e. the auditory canal, changesprogressively. This is obviously true in the case of youngsters growingup, but even the ear canal of adults changes, often considerably, andmostly in a constrictive sense (e.g. the co-called diver's ear).

Conventional in-ear hearing aids, even where their components couldotherwise be expected to be retainable for extended periods in aperson's life, perhaps requiring only a readjustment of the transmissioncharacteristics of the hearing aid in adaptation to the changed auditoryconditions, thus pose a problem in that an all-new hearing aid needs tobe designed repeatedly merely because the previous ones no longer fitproperly into the ear canal.

This can already be improved alone by means of the measures explained inthe above chapter 3) due to the fact that they permit an automaticadaptation of the shape of the custom-moulded ear-plug unit to thechanging area of application. The following will describe additionalmeasures especially for in-ear custom-moulded ear-plug devices. Itshould be pointed out, however, that for outer-ear custom-mouldedear-plugs as well, such as pinnal hearing aids, it becomes possible toreplace the “housing”, and not only when that is necessary for reasonsof wearing-comfort but also, if desired, for instance for changing theaesthetic appearance of such an outer-ear hearing aid.

FIG. 22 shows schematically the longitudinal section of an in-earcustom-moulded ear-plug unit 65, whose inner space 67 conformsessentially to the shape of the electronic module 69, schematicallyillustrated in FIG. 23, that it must accommodate. The custom-mouldedear-plug unit 65 consists of a rubber-like elastic material and, asshown in FIG. 23, can be slipped over the electronic module 69. Theinner space 67 is so contoured that it matches the shape of any moduleto be accommodated which is thus held in place by and in thecustom-moulded ear-plug unit 65. In this fashion it is easily possibleto equip one and the same electronic module 69 with differentcustom-moulded ear-plug units 65, thus permitting an adaptation to thechanging shape of the auditory canal for instance of a growing child.Thus, for all practical purposes, the custom-moulded ear-plug unit usedfor the in-ear hearing aid becomes a replaceable one-way accessory. Thecustom-moulded ear-plug unit 65 can be easily replaced not only tocompensate for changes in the area of application, that being the earcanal, but also when the unit is soiled. This concept may even proveuseful, for instance in the case of an ear infection, for introducingmedication which could be applied on the outside of the custom-mouldedear-plug unit, or in any event for inserting sterilized custom-mouldedear-plug units at regular time intervals.

The concept illustrated in FIGS. 22 and 23 is, of course, combinablewith those presented in chapters 2) and 3), and the custom-mouldedear-plug unit 65 is preferably fabricated by the production methodexplained in chapter 1), which permits the formation of the most complexinternal configurations for the tolerance- and vibration-freeaccommodation of the module 69.

As can be seen in FIG. 22 and 23, the phase plate 1 with whichconventional in-ear hearing aids are equipped, is incorporated as anintegral part for instance of the module mount. The same applies toother mounts and retaining cavities for electronic components of thehearing aid. If the incremental layer-by-layer build-up processexplained in chapter 1) is applied following the dotted line in FIG. 22in the direction of the arrow AB, it should be altogether possible tofabricate the custom-moulded ear-plug unit in the progressive build-updirection AB in accordance with the requirements of each area and from avariety of materials. This also applies to the custom-moulded ear-plugdevices discussed in chapters 2) and 3) and to those described in thefollowing chapters 5), 6) and 7). In reference to the example per FIG.22, it is thus entirely possible to fabricate section 65 _(a) from arubber-like elastic material and the port section 65 _(b) from a morerigid material.

Depicted in FIG. 24 is another design version of an custom-mouldedear-plug unit, again as an example of an in-ear hearing aid whichpermits the simple, rapid exchange of the internal, built-in components.It is recommended that for any such in-ear custom-moulded ear-plug unitwith builtin components, the shell be produced in several assemblablesections as shown in FIG. 24. By means of quick-connect closures such ascatch pawls, detents or even bayonet-type junctions it is possible toquickly separate the housing sections 73 a and 73 b of the in-earcustom-moulded ear-plug unit, remove the internal modules such aselectronic components and reinstall these in a new shell, perhaps onewith a modified outer contour or into an altogether different shell, asmay be necessary for instance for cleaning purposes, sterilerequirements etc. In cases where the used shells must be disposed of, itis entirely possible to configure the shell sections in a way that theycan be opened only in a destructive fashion, rendering them nonreusable,for instance by means of locking elements such as pawls which areinaccessible from the outside, so that it is necessary to cut the shellopen for disposal.

Of course, this design version can on its part be combined with thevariants described above and those yet to be described below.

5. Integration of Acoustic Conductors in Custom-moulded Ear-plug Devicesor their Shells

The input and, respectively, output ends of acoustoelectric inputconverters or electroacoustic output converters in outer-ear as well asin-ear hearing aids are customarily coupled to the auditory environmentby way of discrete, separately assembled acoustic conductors in the formof tubular structures, or, especially for acoustoelectric inputconverters, their receiving surface is positioned in the immediatevicinity of the hearing-aid surface, possibly separated from theenvironment by only small spaces and protective provisions.

The design of hearing aids of that type involves relatively severerestrictions as to where the converter proper and where on the hearingaid the actual interface to the outside world must be positioned. Itwould be highly desirable to have maximum design latitude in theplacement of the interface to the environment and the positioning of theconverters within the hearing aid.

This is entirely feasible in that the acoustic conductors concerned,extending on the input side from acoustoelectric converters and on theoutput side from electroacoustic converters, are integrated directlyinto the custom-moulded ear-plug unit or the wall of the respectivecustom-moulded ear-plug shell.

That is schematically illustrated in FIG. 25. A converter module 75 isprovided with an acoustic input or output 77. Integrated into the shell79 of the custom-moulded ear-plug unit of an in-ear or pinnal hearingaid or an earphone is an acoustic conductor 81 which, at least in partas shown in FIG. 25, extends within the wall of the custom-mouldedear-plug shell 79. Preferably, acoustic stub connectors or line sections83 are employed for tuning the corresponding acoustic impedance of theacoustic conductor 81. With a view to outer-ear hearing aids, thisconcept makes it possible to provide input openings 85 wherever desired,in an offset arrangement along the hearing aid, and to couple these viathe acoustic conductors 89, integrated into the custom-moulded ear-plugunit or its shell 87, to the appropriate acoustoelectric converters 91essentially regardless of where in the hearing aid these converters 91are located. As an example only, shown in FIG. 26, two converters arecentrally positioned and their inputs are connected to the desiredreceiving ports 85 via the above-mentioned acoustic conductor 89. Itwill be evident from FIGS. 25 and 26 and from the discussion in chapter2) of the innovative venting systems that it is entirely possible forthe venting channels to double as acoustic conductors, especially if, asschematically indicated in FIG. 25, acoustic adapters 83 are used fordefining specific acoustic impedance parameters.

6. Labeling of Custom-moulded Ear-plug Units

When custom-moulded ear-plug devices and especially in-ear hearing aidsare manufactured, they are customized for each individual wearer. Itwould therefore be highly desirable to label each such manufacturedcustom-moulded ear-plug unit, especially each in-ear custom-mouldedear-plug device and most particularly each in-ear hearing aid. Hence, itis recommended that each custom-moulded ear-plug unit or its shell beprovided with a recessed or raised labeling area for individualizedmarkings that may include, in addition to the name of the individualbuyer, such information as the manufacturer, product serial number, leftor right ear application, etc. Most preferably, such labeling isproduced during the fabrication of the custom-moulded ear-plug unit bymeans of the ablation process referred to under 1) above. This ensuresthat there can be no mix-up with the custom-moulded ear-plug devices.This is particularly important in the subsequent, possibly automatedassembly process involving additional modules, for instance in theassembly of in-ear hearing aids.

Of course, this step can be combined with any one or several of theprocedures described in chapters 2) to 5) above.

7. Optimization of Custom-moulded Ear-plug Devices Relative to theDynamics of the Area of Application

For the fitting of custom-moulded ear-plug devices intended for in-earapplication, such as in-ear hearing aids, current practice involves thetaking of an impression, for instance in silicone, of the auditorycanal. Considering the relatively substantial dynamics of movement ofthe ear canal, for instance during mastication, it becomes obvious thatsuch an impression, a snapshot as it were, can hardly produce a fit ofthe in-ear custom-moulded ear-plug unit that is entirely satisfactory ineveryday use. Therefore, according to the new method as illustrated bythe simplified functional/signal-flow diagram in FIG. 27, measurementsare taken at several points of statistical dynamic movement in thedynamic application area, represented by the block 93, i.e. the dynamicmovement of the area of application is recorded, frame by frame. Thedata sets thus obtained are stored in a memory module 95. Withconventional impression-based methodology as well, this approach can beimplemented by taking impressions of the area of application at two ormore points representative of the actual dynamic movement.

These impressions are then scanned and the corresponding digital datasets are stored in the memory 95. It would also be possible to usex-rays for acquiring the dynamic data of the application area.

Accordingly, depending on the intended degree of precision, a number of“frames” or, for all practical purposes, a “film strip” of the movementpattern in the application area of interest is recorded. The datarecorded and stored in the memory module 95 are then fed into a computer97. The output end of the computer 97 controls the custom-mouldedear-plug production process 99. If, as is still common practice, thein-ear custom-moulded ear-plugs produced include a relatively hardshell, the computer 97 will use the dynamic data stored in the memory95, as well as perhaps other production parameters as schematicallyindicated at point K, and calculate these for the best fit of thecustom-moulded ear-plug unit so as to assure optimal wearing comfort indaily use without compromising functionality. When the custom-mouldedear-plug unit is fabricated following the principle explained in chapter3), the computer 97 will determine which sections of the custom-mouldedear-plug unit must have what characteristics in terms of flexibility,pliability, compressibility etc. As mentioned above, the output end ofthe computer 97 controls the production process 99, and preferably theproduction process referred to in chapter 1) as the technique of choice.

What is claimed is:
 1. An ear-plug device comprising a shell-having anouter surface forming at least a part of an outer surface of saiddevice, said shell including an area of substantially constant thicknessbetween a substantially smooth outer surface of said area and asubstantially smooth inner surface of said area to form a flexible areaof said shell; at least two elongated reinforcement ribs projectingalong at least one of said inner surface and of said outer surface ofsaid flexible area to locally increase form stability of said flexiblearea, said reinforcement ribs being integral with said shell andprojecting respectively from said substantially smooth outer surface ofsaid area and/or from said substantially smooth inner surface of saidarea, thereby locally increasing the thickness of said shell.
 2. Theear-plug device of claim 1, wherein at least a part of said ribs extendlongitudinally along said device.
 3. The ear-plug device of claim 1,wherein at least a part of said ribs extend circumferentially along saiddevice.
 4. The ear-plug device of claim 1, wherein said ribs projectfrom said inner surface.
 5. The ear-plug device of claim 1, wherein atleast a part of said ribs project from said outer surface of said shell.6. The ear-plug device of claim 5, wherein at least two of said ribsextend longitudinally along said outer surface of said shell andmutually define a continuous open channel along said outer surface. 7.The ear plug device according to claim 1, wherein at least a part ofsaid ribs are arranged in a grid pattern.
 8. The ear plug device ofclaim 1, wherein at least one rib extends helically along said at leastone surface.
 9. The ear plug device of claim 1, wherein at least one ribhas a varying cross-section as considered along said at least one rib.10. The ear plug device of claim 9, wherein said cross-section variesrepeatedly.
 11. The device of claim 10, wherein said cross-sectionvaries periodically.
 12. The ear-plug device of claim 1, wherein saidshell is filled with a material.
 13. The ear-plug device of claim 1,further comprising at least one module within said shell.
 14. Theear-plug device of claim 13, wherein an interspace between said innersurface of said shell and said at least one module is filled with atleast one material.
 15. The ear-plug device of claim 1, said devicebeing an in-the-ear hearing device.
 16. The ear-plug device of claim 1,said device being an in-the-ear hearing aid device.
 17. An ear-plugdevice comprising a device body, said device body including an outersurface, said outer surface having substantially smooth surface areas,said outer surface also having a pattern of elongated projectingreinforcement ribs, said ribs being integral with said body andprojecting from said outer surface by an amount which is considerablyless than a diameter of said ear-plug device.
 18. The ear-plug device ofclaim 17, wherein at least a part of said pattern is formed by said ribsextending longitudinally along said outer surface of said device. 19.The device of claim 17, wherein at least a part of said ribs extendcircumferentially along said device.
 20. The device of claim 17, whereinat least two of said ribs mutually define a continuous open channelalong said device.
 21. The device of claim 17, wherein at least a partof said pattern is a grid pattern.
 22. The ear-plug device of claim 17,wherein said pattern comprises at least one rib extending helicallyalong said device.
 23. The device of claim 17, wherein at least one ofsaid ribs has a varying cross-section as considered along said at leastone rib.
 24. The device of claim 23, wherein said cross-section variesrepeatedly.
 25. The device of claim 24, wherein said cross-sectionvaries periodically.
 26. The device of claim 17, further comprising atleast one functional module within said body.
 27. The device of claim17, wherein said body is full.
 28. The device of claim 17 being anin-the-ear hearing device.
 29. The device of claim 17 being anin-the-ear hearing aid device.
 30. The ear-plug device of claim 17,wherein said device body encompasses substantially all of across-sectional area of an ear canal when said device is inserted intosaid ear canal.
 31. The ear-plug device of claim 30, wherein saidear-plug device substantially blocks sound waves from bypassing saidear-plug device.
 32. An ear-plug device for use in a hearing aid, saiddevice comprising a shell having a substantially constant thickness,said shell including: an outer surface, said outer surface of said shelldefining at least a part of an outer surface of said device; an innersurface; and a plurality of elongated projecting reinforcement ribs uponat least a part of at least one of said inner and of said outersurfaces, said ribs being integral with said shell, wherein non-ribbedportions of said at least one of said inner and of said outer surfacesbetween said ribs are substantially smooth and curved at a radiussubstantially equal to the radius of an ear canal; wherein said deviceis for substantially plugging the width of the ear canal such that soundwaves are substantially prevented from bypassing said device into saidear canal.
 33. The ear-plug device of claim 32, wherein at least aportion of a length of at least one of said ribs extends substantiallyalong the circumference of said shell.
 34. The ear-plug device of claim32, wherein said ribs are of varying width or shape or thickness or anycombination thereof.
 35. The ear-plug device of claim 32, wherein someportion of said ribs are arranged substantially circumferentially alongsaid at least one of said inner and of said outer surfaces while anotherportion of said ribs are arranged substantially longitudinally alongsaid at least one of said inner and of said outer surfaces.
 36. Theear-plug device of claim 32, wherein said ribs are arranged in a gridpattern.
 37. An ear-plug device for use in a hearing aid, said devicecomprising a shell having a substantially constant thickness, said shellincluding: an outer surface defining at least a part of an outer surfaceof said device; an inner surface; and a plurality of elongatedprojecting reinforcement ribs upon at least a part of at least one ofsaid inner and of said outer surfaces, at least one rib of varying widthor shape or thickness, as compared to another rib.
 38. The ear-plugdevice of claim 37, wherein at least one of said ribs has across-sectional shape substantially semi-circular and wherein another ofsaid ribs has a cross-sectional shape substantially rectangular.
 39. Theear-plug device of claim 38, wherein said varying shapes alternateperiodically from one rib to another.
 40. The ear-plug device of claim37, wherein some portion of said ribs are arranged substantiallycircumferentially along said at least one of said inner and of saidouter surfaces while another portion of said ribs are arrangedsubstantially longitudinally along said at least one of said inner andof said outer surfaces.
 41. The ear-plug device of claim 37, whereinsaid ribs are arranged in a grid pattern.
 42. An ear-plug device for usein a hearing aid, said device comprising a shell having a substantiallyconstant thickness, said shell including: an outer surface defining atleast a part of an outer surface of said device; an inner surface; and aplurality of elongated projecting reinforcement ribs upon at least apart of at least one of said inner and of said outer surfaces, at leastone of the width or shape or thickness of one of the ribs varies alongthe length of the rib.
 43. The ear-plug device of claim 42, wherein atleast one of said ribs has a diameter that decreases in thickness alongits length.
 44. The ear-plug device of claim 42, wherein at least one ofsaid ribs has a diameter that first decreases in thickness and thenincreases in thickness along its length in one direction.
 45. Theear-plug device of claim 42, wherein some portion of said ribs arearranged substantially circumferentially along said at least one of saidinner and of said outer surfaces while another portion of said ribs arearranged substantially longitudinally along said at least one of saidinner and of said outer surfaces.
 46. An ear-plug device for use in ahearing aid, said device comprising a shell having a substantiallyconstant thickness, said shell including: an outer surface defining atleast a part of an outer surface of said device; an inner surface; and aplurality of elongated projecting reinforcement ribs upon at least apart of at least one of said inner and of said outer surfaces, said ribsbeing integral with said shell, wherein some portion of said ribs arearranged substantially circumferentially along said at least one of saidinner and of said outer surfaces while another portion of said ribs arearranged substantially longitudinally along said at least one of saidinner and of said outer surfaces.
 47. The ear-plug device of claim 46,wherein said ribs are of varying width or shape or thickness or anycombination thereof.
 48. The ear-plug device of claim 46, wherein saidribs are arranged in a grid pattern.